Revenue Streams can be generated in many ways:

Usage fee
Use of a particular service is sold, the amount to be paid is proportional to the usage. For example, a hotel charges customer by the type of room and nights occupied.

Subscription fees
A continuous or repeated access to a service is sold. For example, a gym sells its members a monthly or yearly subscription for access to its exercise facilities.

Brokerage fees
This type of revenue is derived from an intermediation services performed on behalf of two or more parties. Brokers and real estate agents earn a commission each time they successfully match a buyer with a seller

Advertising
Fees for advertising a particular product, service or brand form the basis of this Revenue Stream. Newspapers and the media industry generally, rely on this approach, which has spread to website advertising and to software sales.

These are a few examples (among the very many) of how to generate revenue streams.